Abstract

Rapid infusion of room temperature intravenous fluids for fluid loading before regional anesthesia may contribute to patient shivering and requires increased patient energy expenditure. Microwave ovens may be useful to warm intravenous fluids rapidly. To develop guidelines for use, four microwave ovens of differing power capacity were used to warm 1-L bags of different intravenous fluids. Time required for warming to a satisfactory temperature was directly related to the power output of the oven. Type of fluid made no difference in warming rate. From these data, suggested warming time guidelines were developed. Caramelization of glucose solutions, significant pH changes, and other untoward effects were not noted. The use of microwave ovens to warm rapidly infused intravenous fluids appears to be safe and efficient, and provides for increased patient comfort.